3-Imino ketones

Wu et al. (156) found that photolysis of 13-substituted dihydroprotober-berine metho salts 296 in methanol similarly afforded the corresponding spirobenzylisoquinolines 297 in 23-54% yields via the quinodimethides (Scheme 53). On the other hand, 13-unsubstituted metho salts 298 furnished, on irradiation, the imino ketones 299 (Scheme 54) instead of spirobenzylisoquinolines through N-demethylation and oxidation via the quinodimethide... 

A recent adaptation of this type of approach involves the spontaneous intramolecular cyclization of imino ketones, formed by the reduction of nitro ketones through the action of tributylphosphine/diphenyl sulfide (Scheme 6.14). When the corresponding esters (R = OR) are used, pyrrolin-2-ones are formed (Scheme 6.15). 

Dipolar cycloaddition reactions between nitrile oxides and aUcenes produce 2-isoxazolines. Through reductive cleavage of the N—O bond of the 2-isoxazohnes, the resulting heterocycles can be readily transformed into a variety of important synthetic intermediates such as p-hydroxy ketones (aldols), p-hydroxy esters, a,p-unsaturated carbonyl compounds, y-amino alcohols, imino ketones and so forth (7-12). 

Reduction of a-imino ketones 52, prepared from 1,2-diketones 51 and 1 equiv of an amine, with sodium in ether, followed by treatment with ethyl chloroformate or... 

TABLE 5.3. CYCLIZATION OF a-IMINO KETONES TO 4,5-DIPHENYL-2(3il)-OXAZOLONES AND 2-THIONES ... 

Die thermische Zersetzung von 2-Aryl-l-azido-2-oxo-ethanen in Diphenylether bei 180-240= fiihrt zu 2-Aroyl-4-aryl-imidazolen (46-84%)229. Analoge Produkte werden auch bei der thermischen Zersetzung von 1,1-Dimethyl-1-(2-oxo-2-phenyl-ethyl)-hydrazinium-Salzen erhal-ten230,231. Bei beiden Reaktionen werden die entsprechenden a-Imino-ketone als Zwischen-produkte angenommen. 

The formation of pyrroles or dihydropyridazines appears to be dependent on the E or Z geometry of the a-imino ketone. 

Photocatalytically active polymer having acridine units in the backbone was synthesized by the polycondensation of 3,6-diaminoacridine (proflavine) as a diamine and m-dibromobenzene (Scheme 13) [68]. Mullen and coworkers synthesized a series of novel poly(imino ketone)s via Pd-catalyzed polycondensation of aromatic dichloro or dibromo ketones with various aromatic diamines (Scheme 14) [69]. The Mw values were in the range of 19500-474 500. The FT-IR spectra of the obtained polymer revealed that in the solid state intermolecular and intramolecular hydrogen bonding (N-H 0=C)... 

The reduction of 2-imino ketones is performed with Bu2SnClH-HMPA to give 2-amino ketones where no reduction of the carbonyl group takes place.84 The reductive amination of carbonyl compounds is one of the most convenient routes to various secondary amines. The high imine selectivity of Bu2SnClH-HMPA can be applied to... 

The title complex represents the parent compound of several known metalla-/3-iminoketone molecules.2 In each case a metalla-/3-diketone molecule is treated with a primary amine, affording the corresponding metalla-/3-imino-ketone derivative. The structure of the cis-tetracarbonylrhenium metalla analogue of N-phenylacetimidoylacetone has been determined.3 The structure of this complex confirms the formulation of these complexes as metalla analogues of the ketamine tautomer of /3-iminoketone molecules. However, the electronic structure is described best by the zwitterionic resonance form shown below. 

The 1 1 reaction of ZnR2 with a-imino ketones R N=C(R")C(0)R" leads to quantitative formation of the dinuclear complexes [ZnR /it-A,O-N(R)(R )C(R")=C(R"0O ]2- The crystal structure of the derivative 238 has been reported. The reaction of [ZnEt(Cp)] and Et2NCH2C02Et gives 239, probably through the intermediate 240. The sodium dialkylamidozincate [(tmeda)Na(/ir-Bu-t)(/ir-TMP)Zn(Bu-t)] reacts with benzophenone to give 241. ... 

Ethylene Imino Ketones by the Action of Amines on tl, S-Dibromo... 

Imino esters—Continued preparation, 483, 634 preparations listed in table 76, 637 pyrolysis to amides, 376 Imino ethers, see Imino esters Imino ketones, preparation, 730 jS-Iminonitriles, hydrolysis, 351 preparation, 730 Indoles, alkylation, 836... 

This synthesis is an example of chelate exchange, the advantages of which are noted later. Attempts to prepare bis(3-phenylimino-l-phenyl-l-butanonato)copper-(II) by direct combination of the /3-keto imine (/3-imino ketone) and ammoniacal copper(II) nitrate have not been successful. However, the compound can be obtained from reaction of the jS-keto imine and bis(4-imino-2-pentanonato)-copper(II) [bis(4-amino-3-penten-2-onato)copper(II)] prepared by the method of Holtzclaw, Collman, and Alire. ... 

Metal derivatives of S-keto imines ( 8-imino ketones), synthesis 13... 

METAL DERIVATIVES OF g-KETO IMINES (5-IMINO KETONES)... 

This reaction is analogous to the preparation of bis(4-imino-2-pentanonato)copper(II) [bis(4-amino-3-penten-2-onato)copper(II)] described by Holtzclaw, Collman, and Alire, and it consists in mixing an ethanolic solution of the -keto imine ( -imino ketone) with an ammoniacal metal salt solution. Advantages of this technique are the simplicity of preparation and the fact that acetylacetone imide (4-imino-2-pentanone) can be purchased. The product is useful as a starting material in ligand-exchange reactions. 

This volume of Inorganic Syntheses contains sixty-eight contributions. Two articles of a review nature are included, one on metal derivatives of jS-keto imines (jS-imino ketones) and the other on the chemistry of the noble gases. 

Two possible routes are suggested for osazone formation under the usual conditions. The first involves formation of the phenylhydrazone, isomerization to an enolic form XLI followed by the loss of aniline to form an imino ketone XLII (or an imino aldehyde from a ketose) which is then converted to the osazone. Isbell depicts this reaction in terms... 

H. Bisulphite Compounds of a-Hydroxy imino Ketones with Potassium Cyanide... 

Reduction ofimines. A mixture of Bu SnClj and Bu SnHj generates BujSnfCljH which saturates imines when complexed with HMPA. Thus, a-amino ketones are obtained from the corresponding imino ketones. Direct reductive amination of carbonyl compounds is also achieved (11 examples, 70-99%). ... 

Dihydropyridazine (36a) was prepared in moderate yield by treatment of substituted a-imino ketones with vinyl triphenylphosphonium bromide [Eq. (6)].88... 

Oxygen instead of nitrogen oi-imino ketones and a-imino esters... 

In order to compare the 1,3-dipolar reactivity of the L4Fe-N—C and the L4Fe-0=C fragments, i.e. to investigate the chemoselectivity of a dipolarophile towards them, a series of suitable complexes with an Fe-N=C and an Fe-0=C fragment within the same molecule, namely [Fe(CO)3(a-imino ketone)] (37) and [Fe(CO)3(a-imino ester)] were prepared and allowed to react with... 

Diazo transfer onto p-imino ketone (249) generally leads directly to 1,2,3-triazole (250). Benzoyl acetaldehyde anil produces 1-phenyl-4-benzoyl- 1,2,3-triazole (250) in 90% yield.1... 

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